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Biomedical subjects

M Lévy

Publications and source records attributed to M Lévy.

15 recordsLinked to original sources
PubMed1990

Evidence for phosphatidylinositol anchorage of opioid binding proteins in rat brain.

Treatment of rat brain sections and of thalamic and striatal membranes with phosphatidylinositol phospholipase C (PIPLC), an enzyme known to hydrolyse only phosphatidylinositol and its derivatives, significantly alters the specific binding of mu- and delta-opioid ligands on their receptors. These results suggest that some opioid binding proteins are membrane-anchored by a glycosylphosphatidylinositol (GPI) linkage.

Animals↗
PubMed1990

[Evaluation of the reagent strip method to detect urinary tract infections. In hospital patients].

Asymptomatic urinary tract infections (UTI) are frequent in hospital patients. Two prospective studies were carried out to evaluate the reagent strip method used to detect these infections. The diagnosis of UTI rested on cytobacteriological examination of urine. Detection by reagent strip was performed either in the microbiology laboratory (study 1:976 samples) or at the patient's bedside and in the laboratory (Study 2:312 samples). The strips were examined visually and by an automated device. There was no significant difference between the results obtained with these two reading methods. Study 1 showed that the reagent strip is more useful to exclude the diagnosis of UTI by using the leucocyte zone alone or combined with the nitrite zone (negative predictive value 98 percent) than to assert this diagnosis. Study 2 showed that the nitrite zone was less sensitive when it was examined at the laboratory than at the patient's bedside. Analysis of discordances between reagent strip and cytobacteriology in the light of data supplied by the patient's medical records made it possible to improve the negative predictive value of the tests. (100 percent). Thus, 60 percent of cytobacteriological examinations might be avoided if this type of examination was performed only in urine with positive leucocyte or nitrite zones. This means a 15 percent saving in B-coded examinations performed in hospital microbiology laboratories.

Hospitals↗
PubMed1990

[Evaluation of the detection of urinary tract infection by the reagent strip method in hospitalized patients].

Asymptomatic urinary tract infections (UTI) are frequent in hospital patients. Two prospective studies were carried out to evaluate the reagent strip method used to detect these infections. The diagnosis of UTI rested on cytobacteriological examination of urine. Detection by reagent strip was performed either in the microbiology laboratory (study 1: 976 samples) or at the patient's bedside and in the laboratory (Study 2: 225 samples). The strips were examined visually and by an automated device. There was no significant difference between the results obtained with these two reading methods. Study 1 showed that the reagent strip is more useful to exclude the diagnosis of UTI by using the leucocyte zone alone or combined with the nitrite zone (negative predictive value 98 percent) than to assert this diagnosis. Study 2 showed that the nitrite zone was less sensitive when it was examined at the laboratory than at the patient's bedside. Analysis of discordances between reagent strip and cytobacteriology in the light of data supplied by the patient's medical records made it possible to improve the negative predictive value of the tests. (100 percent). Thus, 60 percent of cytobacteriological examinations could be avoided if this type of examination was performed only in urine with positive leucocyte and nitrite zones. This means a 15 percent saving in B-coded examinations performed in hospital microbiology laboratories.

France↗
PubMed1990

[Continuous veno-venous hemofiltration in acute renal insufficiency].

A fully pump-assisted continuous veno-venous hemodiafiltration system (CVVHDF) was studied in 10 acute renal failure patients. A counter current pump system ensured slow dialysis at a mean flow rate of 24.6 +/- 0.6 ml/min (single pass) and guaranteed recovery of 97% of dialysate. Ultrafiltration rates were controlled by a separate occlusive pump, connected to the dialysate compartment. Blood was circulated by mean of a third pump at flow rates ranging form 100 to 150 ml/min. Mean duration of CVVHDF was 197 +/- 32 h (range 96-336). Mean serum creatinine and urea before initiation of CVVHDF were 525 +/- 52 mumol/l and 36 +/- 14 mmol/l and stabilized after 4-7 days of CVVHDF at 280 +/- 27 mumol/l and 14 +/- 3 mmol/l. Hemodynamic parameters remained stable. Glucose and phosphate removal by CVVHDF was 296 +/- 42 mmol/day and 33 +/- 6 mmol/day respectively. Fractional losses of aminoacids given by parenteral nutriton averaged 8 +/- 1%. An 69 filters induced no significant changes in leucocyte and thrombocyte counts and only a slight decrease in pO2 (-0.78 +/- 0.30 K Pa at 60 min). We conclude that CVVHDF is a safe, efficient and reliable treatment modality, allowing a good control of the fluid balance.

Acute Kidney Injury↗
PubMed1979

[Choice of a spin label probe in order to study the recombination of beta-hydroxybutyrate dehydrogenase of a rat liver inner mitochondrial membrane with lecithin vesicles].

We find from studying the inhibitory effect of N-ethylmaleimide (NEM) on the enzymatic activity of beta-hydroxybutyrate dehydrogenase, that approximately one molecule of NEM is bound for one molecule of protein when the enzymatic activity is completely inhibited. Since the protein is a dimer this implies that each molecule of protein possesses only one thiol group in its catalytic center. Two long chain maleimide derivates: (10.3) NEM and (1.14) NEM conform, if a reasonable assumption is accepted to the conditions required for the study of the recombination of beta-hydroxybutyrate dehydrogenase with lecithin vesicles by spin label technique.

Animals↗
PubMed1979

Clinicopathologic correlations in the nephrotic syndrome.

The wide utilization of renal biopsy and the introduction of electron microscopic and immunohistologic methods has allowed better definition of the clinico-pathological conditions associated with the nephrotic syndrome (NS). Two major categories of facts can be differentiated. In the first one, diffuse lesions of glomeruli, either secondary to specific diseases, or apparently primary diseases such as membranous or membrano-proliferative glomerulonephropathy (GN) are responsible for the increased permeability of the glomerular capillaries. In most of these, there is evidence that immunological mechanisms play a role in the injury of the glomerular capillary. Any of the following clinical symptoms are suggestive of this category of NS: an acute nephritic onset, a moderate NS, macroscopic hematuria, marked hypertension and/or renal insufficiency, poorly selective proteinuria and decreased plasma C3 levels. Patients affected with any of these glomerulopathies usually do not respond to steroids. In the second one, usually referred to as the idiopathic nephrotic syndrome (INS) the mechanism of glomerular capillary alteration is unknown and the nephrotic syndrome is more marked. Minimal change NS (MCNS) accounts for the great majority of INS and is characterized in most cases by a selective proteinuria, the absence of hematuria, a good response to steroids and a good prognosis. However, in some instances, renal biopsy reveals either diffuse mesangial proliferation (DMP) or focal glomerular sclerosis (which may be superimposed on MCNS or on DMP). In both instances, hematuria may be present and 50--75% of patients do not respond to steroids and have a poor prognosis. There is still considerable controversy about the exact relationship between these 3 patterns. We believe that they are not distinct entities but represent variants of the same disease. In addition to these 2 major categories of NS, there are, in infancy, 2 conditions associated with a NS of poor prognosis: congenital NS of Finnish type and infantile mesangial sclerosis. Since steroid-sensitive nephrosis is by far the commonest cause of NS especially in young children up to 8 years, a renal biopsy should be performed only in 2 instances: (a) when the clinical symptoms suggest diffuse glomerular lesions, and (b) when steroid resistance has been demonstrated.

Adult↗
PubMed1979

[Renal lesions in congenital syphilis. A case report].

The authors describe a case of congenital syphilitic nephropathy in an infant. The review of the reports in the literature shows many similarities of this congenital disease with the syphilitic nephrotic syndrome in the adult. The prognosis is favorable provided the diagnosis is made sufficiently early. Histological studies utilizing light-, electron- and immunofluorescence-microscopy gave results consistent with extramembranous glomerulonephritis with possible evolution towards endo- and extracapillary proliferative glomerulonephritis. This is one of the rare renal diseases with a known antigen.

Antigens, Bacterial↗
PubMed1979

[Complement and nephritic activity in membranoproliferative glomerulonephritis].

A study of complement profiles and of "nephritic activity" (NeF activity) has been carried out in 33 children presenting with membranoproliferative glomerulonephritis (MPGN), in order to determine the pathway of complement activation. By morphological studies two varieties of MPGN have been distinguished. In MPGN with subendothelial deposits, immunofluorescent studies and complement profiles show an activation by the classical pathway. The demonstration of NeF activity in 7 of 20 patients suggests that there is recruitment of the amplification pathway. In MPGN with dense deposits, immunopathological studies indicate an activation of the complement system through the alternate pathway, NeF activity being present in 10 of 13 patients. With the functional tests used, it is not possible to ascertain that the factors responsible for the NeF activity in MPGN with subendothelial deposits are identical to the C3NeF identified in MPGN with dense deposits and/or partial lipodystrophy.

Capillaries↗
PubMed1978

[Pulmonary hemosiderosis in children. Immunologic study].

Circulating anti alveolar basement membrane antibodies have been detected by indirect immunofluorescence on lung rat in two out of five children presenting with pulmonary hemosiderosis. The two cases are reported and seem to be consistent with an auto-immune disease due to anti-basement membrane antibodies. Authors outline the presence of anti-reticulin antibodies in the two cases reported and the high level of IgE which seems a frequent finding in pulmonary hemosiderosis.

Animals↗
PubMedDate not supplied

[Partial lipodystrophy, hypocomplementemia and glomerulonephritis].

Renal involvement is found in 20 to 50% of cases of Partial lipodystrophy (PLD). We report 8 cases of PLD of which 6 had a glomerular nephropathy and 2 had no renal disease but all had persistent hypocomplementemia and 5 had circulating nephritic factor (C3NeF). The analysis of these cases and of all the cases reported in the literature shows the specificity of the glomerular involvement. Membranoproliferative glomerulonephritis (MPGN) with dense intramembranous deposits is a constant finding in PLD with renal involvement. This variety of MPGN is well known for being associated with persistent hypocomplementemia. However, the presence of hypocomplementemia and C3NeF in patients with PLD but without nephritis raises the question of the interrelationship between alternative pathway complement activation and the development of MPGN with or without lipodystrophy. There is no valid explanation in the present state of knowledge for the association of partial lipodystrophy hypocomplementemia, and MPGN. From the answer to this problem should emerge a better understanding of the role of complement in renal disease and in particular in the unusual form of glomerular injury seen in MPGN.

Adolescent↗